JP6131071B2 - Touch panel built-in display device - Google Patents

Description

  The present invention relates to a touch panel built-in display device.

  In recent years, touch panel technology that supports a human-friendly graphical user interface has become important in the spread of mobile devices. As this touch panel technology, a capacitive bonding type touch panel is known, and a general capacitive bonding type touch panel is provided with a touch panel substrate in which a conductive coating (transparent conductive film) is applied on the surface of a glass substrate. The position is detected by touching the finger here. There is also known a liquid crystal display panel with a touch panel that performs an operation corresponding to a menu by attaching the touch panel substrate to the surface of the liquid crystal display panel and touching a menu screen displayed on the liquid crystal display panel with a finger ( Patent Document 1).

JP 2006-146895 A

  In general, a display panel with a touch panel is used by overlapping a touch panel on the display area surface of the display panel for displaying images and character information. However, in a conventional display panel with a touch panel, the touch panel and the display panel are separately provided. Are manufactured and combined to form the final product. Therefore, in the conventional display panel with a touch panel, since the touch panel manufactured separately and a display panel need to be stacked | stacked, there existed a problem that a display panel with a touch panel became thick.

  An object of the present invention is to provide a display device with a built-in touch panel that can be made thinner than the conventional one by incorporating a touch panel.

  (1) A touch panel built-in display device according to the present invention includes a first substrate, a second substrate, a plurality of pixel electrodes formed between the first substrate and the second substrate, the first substrate, An electric field generated between the plurality of pixel electrodes and the plurality of common electrodes, the plurality of common electrodes formed between the second substrate and a plurality of detection electrodes formed on the first substrate; An image is displayed by controlling the light using the sensor, and the presence or absence of a touch is detected by a difference in capacitance due to the presence or absence of a substance that blocks an electric field formed between any of the detection electrodes and any of the common electrodes. Each of the detection electrodes has a through hole. According to the present invention, since the touch panel is incorporated, it is thinner than the conventional display device with a touch panel. Moreover, since the detection electrode has a through hole, the number of edges increases. Therefore, the electric field formed in the opposing region of the detection electrode and the common electrode decreases, and the fringe electric field that wraps around from both outside increases. A fringe electric field is used to detect the presence or absence of a touch. Therefore, the detection sensitivity can be improved by increasing the fringe electric field.

  (2) In the display device with a built-in touch panel described in (1), a land portion in an electrically floating state may be provided inside the through hole.

  (3) In the display device with a built-in touch panel described in (1) or (2), the plurality of detection electrodes are arranged with an interval between adjacent ones, and between the adjacent detection electrodes, electrical A dummy electrode in a floating state may be included, and the dummy electrode may have a dummy through hole.

  (4) In the display device with a built-in touch panel described in (3), a dummy land portion in an electrically floating state may be provided inside the dummy through hole.

  (5) In the display device with a built-in touch panel described in any one of (1) to (4), the plurality of common electrodes extend in the horizontal direction and are adjacent to each other in the vertical direction. The electrodes may be characterized in that they extend in the vertical direction and are adjacent to each other in the horizontal direction.

It is sectional drawing of the touchscreen built-in type display apparatus which concerns on embodiment of this invention. 1 is an exploded perspective view of a main part of a display device with a built-in touch panel according to an embodiment of the present invention. It is a figure which shows the circuit for displaying an image on a display panel. It is a top view which shows the detail of a detection electrode. It is a figure which shows the electric field formed between a detection electrode and a common electrode. It is a figure for demonstrating the effect | action which detects the presence or absence of a touch. It is a figure which compares an Example and a prior art example about the change of the capacity | capacitance by the presence or absence of a touch. It is a figure which shows the modification 1 of this embodiment. It is a figure which shows the modification 2 of this embodiment. It is a figure which shows the modification 3 of this embodiment.

  FIG. 1 is a cross-sectional view of a display device with a built-in touch panel according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a main part of the display device with a built-in touch panel according to the embodiment of the present invention. Although the following description is an example in which the present invention is applied to a liquid crystal display device, the present invention can also be applied to a display device other than the liquid crystal display device (for example, an EL (Electro Luminescence) display device).

  The touch panel built-in display device includes a first substrate 10 and a second substrate 12. A liquid crystal material 14 is disposed between the first substrate 10 and the second substrate 12. Alignment films 16 are formed between the first substrate 10 and the second substrate 12 at positions where the liquid crystal material 14 is sandwiched.

  The first substrate 10 is made of a light transmissive material (for example, glass). The first substrate 10 is a color filter substrate, on which a colored layer and a black matrix (not shown) are formed. An alignment film 16 is formed on the first substrate 10. The alignment film 16 is formed on a colored layer and a black matrix (not shown).

  The second substrate 12 is made of a light transmissive material (for example, glass). The second substrate 12 is also called a TFT substrate because a thin film transistor 18 is formed. The thin film transistor 18 includes a semiconductor film 20 such as polysilicon, a gate insulating film 22 covering the semiconductor film 20, a gate electrode 24 disposed above the semiconductor film 20 with the gate insulating film 22 interposed therebetween, and the gate insulating film 22. A source electrode 26 and a drain electrode 28 which penetrate and are electrically connected to the semiconductor film 20.

  One of the source electrode 26 and the drain electrode 28 is electrically connected to the pixel electrode 30. A common electrode 34 is formed at a layer position different from that of the pixel electrode 30 with the insulating film 32 interposed therebetween. In the example of FIG. 1, the pixel electrode 30 is located above the common electrode 34 (on the side away from the second substrate 12), but may be disposed upside down.

  The liquid crystal display panel 36 is composed of the above components. An image is displayed by controlling light using an electric field generated between the plurality of pixel electrodes 30 and the plurality of common electrodes 34. In the present embodiment, the liquid crystal material 14 is driven by an electric field formed between the pixel electrode 30 and the common electrode 34. Since the pixel electrode 30 and the common electrode 34 are formed on the second substrate 12, the electric field formed between the pixel electrode 30 and the common electrode 34 is a lateral electric field. Alternatively, the pixel electrode 30 may be formed on the second substrate 12, the common electrode 34 may be formed on the first substrate 10, and the liquid crystal material 14 may be driven by a vertical electric field. In any configuration, the pixel electrode 30 and the common electrode 34 are disposed between the first substrate 10 and the second substrate 12.

  The display device with a built-in touch panel has a detection electrode 38 formed on the first substrate 10. In the example of FIG. 1, the detection electrode 38 is disposed on the surface of the first substrate 10 opposite to the liquid crystal material 14. As shown in FIG. 2, the plurality of common electrodes 34 extend in the horizontal direction and the adjacent ones are arranged in the vertical direction.

  The presence / absence of a touch is detected by the difference in capacitance due to the presence / absence of a substance that blocks the electric field formed between the detection electrode 38 and the common electrode 34. Specifically, different voltages are applied to the detection electrode 38 and the common electrode 34 to form an electric field (fringe electric field) between the two (specifically, outside the opposing region). The presence / absence of a touch is detected based on the difference in capacitance due to the presence / absence of a substance (for example, finger 40) that blocks the electric field formed between the detection electrode 38 and the common electrode 34. That is, the touch panel 42 is configured by the first substrate 10, the detection electrode 38, and the common electrode 34. A front panel 46 is attached to the touch panel 42 via an adhesive layer 44 to be reinforced.

  According to the present embodiment, since the touch panel 42 is built in, the apparatus can be made thinner than before. In addition, since the liquid crystal display panel 36 and the touch panel 42 share the first substrate 10, it is not necessary to take measures against misalignment between them.

  The first substrate 10 has a rectangular planar shape, and a plurality of detection electrodes 38 extend in the vertical direction along the long side. A flexible wiring substrate 48 is attached to the first substrate 10 for electrical connection between the detection electrode 38 and the outside. An integrated circuit chip 50 incorporating a liquid crystal drive circuit is mounted on the second substrate 12, and a flexible wiring substrate 52 is attached for electrical connection with the outside.

  FIG. 3 is a diagram showing a circuit for displaying an image on the liquid crystal display panel 36. A pixel electrode 30 is formed in the image display area 56. Since pixels are formed by the plurality of pixel electrodes 30, an area surrounding the plurality of pixel electrodes 30 is an image display area 56. A common electrode 34 is formed in the image display area 56. The common electrode 34 is set to a reference potential (for example, GND), and a voltage corresponding to the brightness of the pixel is applied to the pixel electrode 30. An image is displayed by controlling light using an electric field generated between the pixel electrode 30 and the common electrode 34 (for example, driving the liquid crystal material 14).

  The common electrode 34 is electrically connected to the common wiring 58, and the pixel electrode 30 is electrically connected to the signal line 60. A switching element 62 (for example, the thin film transistor 18 shown in FIG. 1) is connected between the pixel electrode 30 and the signal line 60 so that the pixel electrode 30 and the signal line 60 can be electrically connected and disconnected. . The switching element 62 is connected to a scanning line 64 drawn from a scanning circuit (not shown), and is driven (ON / OFF) by a scanning signal input to the scanning line 64.

  FIG. 4 is a plan view showing details of the detection electrode 38. The plurality of detection electrodes 38 extend in the vertical direction and are adjacent to each other in the horizontal direction. The plurality of common electrodes 34 indicated by broken lines extend in the horizontal direction and are adjacent to each other in the vertical direction. The plurality of detection electrodes 38 are arranged with an interval between adjacent ones. The fringe electric field can be increased by increasing the interval. The detection electrode 38 has a through hole 38a. The detection electrode 38 is made of a conductive material having a high visible light transmittance, such as ITO (Indium Tin Oxide), but is easily visible from the outside as the film thickness increases. Therefore, by forming a through hole 38a in the detection electrode 38, the detection electrode 38 is difficult to see and the image is easy to see.

  A dummy electrode 54 is disposed between the adjacent detection electrodes 38. There is a gap between the detection electrode 38 and the dummy electrode 54. In the example of FIG. 4, a plurality of dummy electrodes 54 are arranged between adjacent detection electrodes 38 at intervals in the interval direction. In addition, a plurality of dummy electrodes 54 are also arranged at intervals in a direction (longitudinal direction) in which the detection electrodes 38 extend. The dummy electrode 54 is formed of the same material as the detection electrode 38. By disposing the dummy electrode 54 between the detection electrodes 38, it is possible to make the detection electrodes 38 difficult to view, thereby making it easier to see the image.

  The dummy electrode 54 is in an electrically floating state. That is, the dummy electrode 54 is not connected to a reference potential such as GND, and is not connected to the detection electrode 38 or other wiring. However, the dummy electrode 54 may be connected to a reference potential such as GND as necessary. A plurality of dummy electrodes 54 are arranged with an interval between adjacent ones. The dummy electrode 54 has a dummy through hole 54a. By disposing the dummy electrode 54, the region where the conductor does not exist is narrowed and the fringe electric field is reduced. However, since the dummy through hole 54a is formed, the amount of decrease in the fringe electric field is small. Further, by forming the dummy through hole 54a, the dummy electrode 54 becomes difficult to visually recognize, and the image is easy to see.

  FIG. 5 is a diagram illustrating an electric field formed between the detection electrode 38 and the common electrode 34. An electric field (normal electric field) is generated in the opposing region (between the opposing surfaces) between the detection electrode 38 and the common electrode 34 as indicated by the lines of electric force. Further, a fringe electric field is generated as shown by the lines of electric force while avoiding the opposing region of the detection electrode 38 and the common electrode 34. Many fringe electric fields are distributed between the edge of the detection electrode 38 and the common electrode 34. Since the detection electrode 38 has the through hole 38a, the number of edges increases. For this reason, the normal electric field formed in the region facing the detection electrode 38 and the common electrode 34 decreases, and the fringe electric field that wraps around from both outside increases.

  FIG. 6 is a diagram for explaining the operation of detecting the presence or absence of a touch. A fringe electric field is used to detect the presence or absence of a touch. For example, when there is a touch with a finger, the finger 40 becomes GND and shields the fringe electric field. As a result, the capacitance formed between the detection electrode 38 and the common electrode 34 decreases, so that the presence or absence of touch can be detected by detecting the decrease (capacity difference).

  In the present embodiment, as described above, since the through hole 38a is formed in the detection electrode 38, the fringe electric field is increased. When there is a touch, the increased fringe electric field is shielded, so that the capacitance is greatly reduced. Therefore, the touch detection sensitivity can be improved.

FIG. 7 is a diagram comparing an example and a conventional example with respect to a change in capacitance depending on the presence or absence of touch. From T ₁ may touch a period of T _2, there is shown a change in capacitance in the graph. Compared to the conventional example, it can be seen that in the example, the change in capacitance (capacity difference) due to the presence or absence of touch is larger. In an embodiment, for example, capacity is determined that there is a touch when it is detected that becomes smaller than C _1, the capacitance is determined that there is no detection to the touch that is larger than C ₂ Design the circuit as follows. C ₁ and is preventing erroneous operation by the C ₂ providing a difference, malfunction hardly larger the difference. In the embodiment, since the change in capacitance (capacity difference) due to the presence or absence of touch is large, the difference between C ₁ and C ₂ can be increased. As a result, it is possible to prevent a malfunction that erroneously recognizes the presence or absence of a touch.

  FIG. 8 is a diagram illustrating a first modification of the present embodiment. In this example, the detection electrode 138 has a land portion 166 in an electrically floating state inside the through hole 138a. By providing the land portion 166, it is possible to make the through-hole 138a difficult to visually recognize, thereby making it easier to see the image.

  FIG. 9 is a diagram illustrating a second modification of the present embodiment. In this example, the dummy electrode 254 includes a dummy land portion 266 in an electrically floating state inside the dummy through hole 254a. By providing the dummy land portion 266, it is possible to make the dummy through hole 254a difficult to visually recognize, thereby making it easier to view the image.

  FIG. 10 is a diagram showing a third modification of the present embodiment. In this example, the dummy electrodes are eliminated and the interval between the adjacent detection electrodes 338 is narrowed. In order to reduce the interval between the detection electrodes 338, the width of the detection electrodes 338 can be increased to reduce the resistance. Further, since the interval is narrow, it is difficult to visually recognize the detection electrode 338, thereby making it easy to see the image. In addition, since the region through which the lines of electric force pass is narrowed by narrowing the interval between the adjacent detection electrodes 338, the through hole 338a is formed even if the fringe electric field passing between the adjacent detection electrodes 338 becomes weak. As a result, the fringe electric field is increased.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the configuration described in the embodiment can be replaced with substantially the same configuration, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose.

  10 first substrate, 12 second substrate, 14 liquid crystal material, 16 alignment film, 18 thin film transistor, 20 semiconductor film, 22 gate insulating film, 24 gate electrode, 26 source electrode, 28 drain electrode, 30 pixel electrode, 32 insulating film, 34 common electrode, 36 liquid crystal display panel, 38 detection electrode, 38a through hole, 40 fingers, 42 touch panel, 44 adhesive layer, 46 front panel, 48 flexible wiring board, 50 integrated circuit chip, 52 flexible wiring board, 54 dummy electrode, 54a dummy through hole, 56 image display area, 58 common wiring, 60 signal line, 62 switching element, 64 scanning line, 138 detection electrode, 138a through hole, 166 land portion, 254 dummy electrode, 266 dummy land portion, 338 detection electrode 338a Through hole.

Claims (5)

A first substrate;
A second substrate;
A plurality of pixel electrodes formed between the first substrate and the second substrate;
A plurality of common electrodes formed between the first substrate and the second substrate;
A plurality of detection electrodes formed on the first substrate;
Have
Displaying an image by controlling light using an electric field generated between the plurality of pixel electrodes and the plurality of common electrodes;
Detecting the presence or absence of touch by the difference in capacitance due to the presence or absence of a substance that blocks the electric field formed between any of the detection electrodes and any of the common electrodes;
Each of the detection electrodes, have a plurality of circular through holes formed so as to face the common electrode,
The plurality of detection electrodes are arranged with an interval between adjacent ones,
Between the adjacent detection electrodes, there is a dummy electrode in an electrically floating state,
The dummy electrode, a touch panel built-in display device, characterized in that it have a dummy through hole. The display device with a built-in touch panel according to claim 1,
A display device with a built-in touch panel, wherein a land portion in an electrically floating state is provided inside the plurality of circular through holes. The touch panel built-in display device according to claim 1 or 2 ,
A display device with a built-in touch panel, wherein a dummy land portion in an electrically floating state is provided inside the dummy through hole. In the touch panel built-in display device according to any one of claims 1 to 3 ,
The plurality of common electrodes extend in the horizontal direction and are adjacent to each other in the vertical direction.
The display panel with a built-in touch panel, wherein the plurality of detection electrodes extend in the vertical direction and are adjacent to each other in the horizontal direction. A first substrate;
A second substrate;
A plurality of pixel electrodes formed between the first substrate and the second substrate;
A plurality of common electrodes formed between the first substrate and the second substrate;
A plurality of detection electrodes formed on the first substrate;
Have
Displaying an image by controlling light using an electric field generated between the plurality of pixel electrodes and the plurality of common electrodes;
Detecting the presence or absence of touch by the difference in capacitance due to the presence or absence of a substance that blocks the electric field formed between any of the detection electrodes and any of the common electrodes;
Each of the detection electrodes has a plurality of circular through holes formed to face the common electrode,
The plurality of common electrodes extend in the horizontal direction and are adjacent to each other in the vertical direction with a first interval region,
The plurality of detection electrodes extend in the vertical direction and are adjacent to each other with a second interval in the horizontal direction.
The second interval is wider than the first interval;
The plurality of circular through holes are formed to avoid overlapping with the region of the first interval,
A display device with a built-in touch panel, wherein an interval between the two circular through holes formed across the region of the first interval is wider than the first interval.

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